1. Field of the Invention
The present invention relates to extracting and managing knowledge regarding a manufacturing process, and more particularly to externalizing manufacturing strategy and know how from engineering design, analysis and manufacturing and planning systems and to integrate knowledge, standards and applications for the manufacturing process.
2. Brief Description of the Related Arts
The design of parts, tools, computer chips etc. have seen incredible advances, especially in the time it takes to go from the design phase to actually manufacturing the part or tool. This renaissance has been brought about mainly by the advent of the computer and specialized software. Conventionally, there are four important types of software programs that are used to facilitate the process from the design phase to the manufacturing phase, as shown in Prior Art FIG. 1.
In a design phase, Computer-Aided Design (CAD) software combines the techniques of drafting and computer graphics to produce models of parts and tools to be manufactured and represents the part or tool geometry in computer language. These models can be manipulated and tested via video display screens until they incorporate the best attainable balance of features, as well as including ease of production and lower cost.
Popular CAD programs include CATIA, Unigraphics, Pro Engineer, AutoCad and Solidworks among others. The CAD program stores the shapes entered as computer files generally in a proprietary format.
A CAD system typically includes the CAD software, a high-end computer workstation, a high-quality graphics monitor, a mouse, light pen, or digitizing tablet for drawing and a printer or plotter for printing design specifications and is often coupled with Computer-Aided Manufacturing (CAM) software through shared databases. CAM systems provide the ability to convert the geometry generated by the CAD program into machining or tool path instructions to make the part on a router, milling machine, lathe or any Computer Numerically Controlled (CNC or NC) machine.
The primary function of CAM programs is the generation of machining instructions to produce parts, tools, etc., taking into account tool or part features such as shape, diameter, thickness, etc. CAM systems are offered by leading CAD vendors such as CATIA, Unigraphics, Pro-Engineer and various independent system vendors such as MasterCam, SurfCam and Gibbs among others.
CAM programs store tool path information, in a file, as a set of executable motion instructions. The format for these commands can be unique to a particular program or a universally accepted standard. The most common standard format is the APT machine tool command language. APT is a common format that can be converted into a set of unique commands used by each CNC machine. The tool path created in the CAM software package is translated into a machine specific G-Code format with the application of a post-processor. Post-processing software accepts the tool path information and allows the user to customize the tool path commands for a particular CNC controller or machine. This post-processing allows for machine specific instructions such as startup and shut down, tool changers, canned cycles or special format requirements.
Process planning systems capture high level steps necessary to create the part. This includes material information, general manufacturing processes, company standards to apply, general instructions, and quality assurance steps.
Process planning systems generally capture “what” each step is as opposed to the details of how each step is performed. For example, a typical system will call out “Set up 1: Rough Part features on Datum A side”. The exact instructions, such as what cutters to use, what machining strategies to implement, and the cutting computation, are not captured.
Process planning is usually performed on many different software applications of varying capability. This can be as simple as a standard word processor, an internally developed software tool, or a commercial tool such as HMS-CAPP from HMS Software Inc.
Despite the advances in CAD, CAM, NC machines and process planning systems, as described above, the traditional process still imbeds detailed manufacturing strategies within the NC program, process planning system and is also scattered among other documents, such as engineering drawings, local best practices, mental impressions, trade secrets, etc. Since this valuable knowledge on how the part or object should be optimally manufactured can only be defined within a multitude of proprietary systems, the prior art has several deficiencies in this regard, such as: a) NC programming cannot begin until CAD geometry is released; b) moving parts between suppliers requires significant rework to “reinvent” the manufacturing strategies because there is currently no way to communicate the proven method; c) manufacturing strategy is “buried” in software system settings and data files which are not easily transferable between users; d) the best practices are extremely difficult to capture, share, and implement; e) ensuring standards are being adhered to is difficult; and f) controlling the quality across the NC programmer staff which is dependent solely on programming experience.
The prior art is deficient in providing a manufacturing strategy that is externalized from the multitude of manufacturing software systems and expertise that is capable of providing system manufacturing optimization, cost estimates, and tool path instruction, from among a host of functions, and is available for review, optimization, and communication concurrently with the design phase, thus allowing for more accurate cost estimates, identification of producibility issues and the quantification of each issue, the selection of manufacturing centers with capabilities necessary to optimize part manufacturing, and the implementation of automated machining instructions, that all can be generated and/or accessed from a library of proven manufacturing strategies. The prior art is also deficient in not providing a method for outsourcing that can be controlled by providing suppliers a proven manufacturing strategy to follow.
The prior art also does not address issues regarding quality of NC programmers and other post operations and does not ensure quality control providing for “best-in-class” templates to support the manufacturing process.